Compaq Presario 700 laptop shut down problem

I have a presario 700 it shuts down after a couple of minutes. I tried just booting to BIOS and same thing happens. It's probably a heat issue but is there anyone with a suggestion to remedy the situation?

Fan works but it is mostly on high. The BIOS stinks doesn't have much to choose from and temp is not an option. I am going to try the dusting hopefully that will be a quick fix. thanks for the response.